For the winding of narrow webs or strips of paper, foil or the like and especially strips of the thinnest foils as may be used in the fabrication of condensers, a multiplicity of winding sleeves can be provided on an equal number of clamping heads with swingable arms disposed one alongside another. The swingable support arms are pivotally mounted at their pivoted ends on a common pivot axis to swing in the machine frame. The mounting of empty winding sleeves on the clamping heads and the removal of finished rolls in such systems is time consuming since, for that purpose, the swing arms must by swung into an unloading position. In this position, the finished roll must be removed and an empty or new winding sleeve set upon the head.
For this purpose in the conventional clamping arrangement, the two rings are coupled together by outer and inner threads which require that a screwing operation be carried out to displace the rings apart and together axially.
A bronze ring is provided between the two clamping rings, each of which has an inclined surface so that, depending upon the axial positions of the clamping rings, the resilient ring can either be pressed outwardly to engage the sleeve or retracted inwardly to release the sleeve.
The relative rotation which effects the screwing action requires special tools, namely, one tool to hold one of the clamping rings in place, i.e. a tool with projecting pins which can engage through an opening in the support arm, and a tool engageable with the other clamping ring from the opposite side. Bores or suitably shaped recesses engageable by the tools must also be provided.
With the aid of the two tools, the clamping rings can be relatively rotated so that the bronze ring is displaced outwardly or inwardly. The bronze ring moves inwardly because of its intrinsic resiliency.
One of the problems with this earlier system is that the bronze ring cannot guarantee an effective clamping of the sleeve to insure uniform winding of the strip thereon. Frequently, the sleeve is compacted to an extent that the finished roll cannot be removed and inner turns of the roll may not be under the same radial pressure as outer turns thereof.
It has been proposed to obviate this problem by providing elastic rings which can be set into the outer surface of the bronze ring, e.g. in the form of rubber O-rings. Nevertheless, the amount of handling, the time required for mounting a new sleeve and dismounting a finished rod through the use of special tools, and the like have made the cost of operation of such systems prohibitive and has caused the rolls to vary in hardness in spite of the greatest care of the personnel operating the system
German Open Application 24 59 231 describes a coiling machine of the aforedescribed type in which one of the clamping rings has an inclined surface which cooperates with a spring ring to press the latter against the inner surface of the winding sleeve. The two clamping rings are directly connected via inner and outer screw threads so that a relative rotation of the two rings is essential to effect the displacement which presses the spring ring outwardly along the inclined surface or, inversely, allows the intrinsic resiliency of the spring ring to draw this ring inwardly and release the sleeve. For the release process a special pressing button is required and is accessible through an opening in the support arm for engagement in an opening of a respective ring to secure the latter against rotation.
In this system, it is a disadvantage that the button must be pressed during the entire releasing operation since the relative axial positions of the two rings can be adjacent exclusively by the screwing action of the screw threads. There is a danger that there will be undesirable shifting and a jamming of the system. In manual operation it is possible during rotation of the second ring by insertion of the fingers in corresponding finger openings that a finger can come into contact with the first or stationary disk or ring and result in injury to the operator.
In an alternative construction, the pushbutton can be eliminated but, in this case, tools are required to achieve the relative rotation of the two rings with the drawbacks outlined above.